Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932454AbdIFO0A (ORCPT ); Wed, 6 Sep 2017 10:26:00 -0400 Received: from mail-wr0-f201.google.com ([209.85.128.201]:54916 "EHLO mail-wr0-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754611AbdIFOZ4 (ORCPT ); Wed, 6 Sep 2017 10:25:56 -0400 X-Google-Smtp-Source: ADKCNb7trhPQZkw9QRvQOIrIxJwh3958VgGhmFYVOJmbFhx+vOp8o8CegewApHjl8k1G9HclSeDwotYDFA== MIME-Version: 1.0 Date: Wed, 6 Sep 2017 16:25:01 +0200 Message-Id: <20170906142502.11783-1-tweek@google.com> X-Mailer: git-send-email 2.14.1.581.gf28d330327-goog Subject: [PATCH 1/2] efi: call get_event_log before ExitBootServices From: Thiebaud Weksteen To: linux-efi@vger.kernel.org Cc: matt@codeblueprint.co.uk, linux-kernel@vger.kernel.org, mjg59@google.com, tpmdd-devel@lists.sourceforge.net, peterhuewe@gmx.de, Thiebaud Weksteen Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10471 Lines: 312 With TPM 2.0, access to the event log is only possible by using the EFI TPM2 Boot Service. Modify the EFI stub to copy the log area to a new Linux-specific EFI table so it remains accessible for future use. Signed-off-by: Thiebaud Weksteen --- arch/x86/boot/compressed/eboot.c | 1 + drivers/char/tpm/tpm.h | 29 ++++++++++--- drivers/char/tpm/tpm_eventlog.h | 26 +++--------- drivers/firmware/efi/libstub/Makefile | 3 +- drivers/firmware/efi/libstub/tpm.c | 80 +++++++++++++++++++++++++++++++++++ include/linux/efi.h | 35 +++++++++++++++ 6 files changed, 146 insertions(+), 28 deletions(-) diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index a1686f3dc295..97bec8df36ff 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -999,6 +999,7 @@ struct boot_params *efi_main(struct efi_config *c, /* Ask the firmware to clear memory on unclean shutdown */ efi_enable_reset_attack_mitigation(sys_table); + efi_retrieve_tpm2_eventlog(boot_params, sys_table); setup_graphics(boot_params); diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 04fbff2edbf3..efede7dc9340 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -40,6 +40,8 @@ #include #endif +#include "tpm_eventlog.h" + enum tpm_const { TPM_MINOR = 224, /* officially assigned */ TPM_BUFSIZE = 4096, @@ -397,11 +399,6 @@ struct tpm_cmd_t { tpm_cmd_params params; } __packed; -struct tpm2_digest { - u16 alg_id; - u8 digest[SHA512_DIGEST_SIZE]; -} __packed; - /* A string buffer type for constructing TPM commands. This is based on the * ideas of string buffer code in security/keys/trusted.h but is heap based * in order to keep the stack usage minimal. @@ -581,4 +578,26 @@ int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u32 cc, u8 *cmd); int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space, u32 cc, u8 *buf, size_t *bufsiz); + +extern const struct seq_operations tpm2_binary_b_measurements_seqops; + +#if defined(CONFIG_ACPI) +int tpm_read_log_acpi(struct tpm_chip *chip); +#else +static inline int tpm_read_log_acpi(struct tpm_chip *chip) +{ + return -ENODEV; +} +#endif +#if defined(CONFIG_OF) +int tpm_read_log_of(struct tpm_chip *chip); +#else +static inline int tpm_read_log_of(struct tpm_chip *chip) +{ + return -ENODEV; +} +#endif + +int tpm_bios_log_setup(struct tpm_chip *chip); +void tpm_bios_log_teardown(struct tpm_chip *chip); #endif diff --git a/drivers/char/tpm/tpm_eventlog.h b/drivers/char/tpm/tpm_eventlog.h index b4b549559203..1009a2503985 100644 --- a/drivers/char/tpm/tpm_eventlog.h +++ b/drivers/char/tpm/tpm_eventlog.h @@ -104,6 +104,11 @@ struct tcg_event_field { u8 event[0]; } __packed; +struct tpm2_digest { + u16 alg_id; + u8 digest[SHA512_DIGEST_SIZE]; +} __packed; + struct tcg_pcr_event2 { u32 pcr_idx; u32 event_type; @@ -112,26 +117,5 @@ struct tcg_pcr_event2 { struct tcg_event_field event; } __packed; -extern const struct seq_operations tpm2_binary_b_measurements_seqops; - -#if defined(CONFIG_ACPI) -int tpm_read_log_acpi(struct tpm_chip *chip); -#else -static inline int tpm_read_log_acpi(struct tpm_chip *chip) -{ - return -ENODEV; -} -#endif -#if defined(CONFIG_OF) -int tpm_read_log_of(struct tpm_chip *chip); -#else -static inline int tpm_read_log_of(struct tpm_chip *chip) -{ - return -ENODEV; -} -#endif - -int tpm_bios_log_setup(struct tpm_chip *chip); -void tpm_bios_log_teardown(struct tpm_chip *chip); #endif diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index dedf9bde44db..2abe6d22dc5f 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -29,8 +29,7 @@ OBJECT_FILES_NON_STANDARD := y # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. KCOV_INSTRUMENT := n -lib-y := efi-stub-helper.o gop.o secureboot.o -lib-$(CONFIG_RESET_ATTACK_MITIGATION) += tpm.o +lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o # include the stub's generic dependencies from lib/ when building for ARM/arm64 arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c index 6224cdbc9669..ba2cb68833fb 100644 --- a/drivers/firmware/efi/libstub/tpm.c +++ b/drivers/firmware/efi/libstub/tpm.c @@ -4,6 +4,7 @@ * Copyright (C) 2016 CoreOS, Inc * Copyright (C) 2017 Google, Inc. * Matthew Garrett + * Thiebaud Weksteen * * This file is part of the Linux kernel, and is made available under the * terms of the GNU General Public License version 2. @@ -12,7 +13,9 @@ #include #include "efistub.h" +#include "../../../char/tpm/tpm_eventlog.h" +#if IS_ENABLED(CONFIG_RESET_ATTACK_MITIGATION) static const efi_char16_t efi_MemoryOverWriteRequest_name[] = { 'M', 'e', 'm', 'o', 'r', 'y', 'O', 'v', 'e', 'r', 'w', 'r', 'i', 't', 'e', 'R', 'e', 'q', 'u', 'e', 's', 't', 'C', 'o', 'n', 't', 'r', 'o', @@ -56,3 +59,80 @@ void efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg) EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, sizeof(val), &val); } + +#endif + +void efi_retrieve_tpm2_eventlog_1_2(struct boot_params *boot_params, + efi_system_table_t *sys_table_arg) +{ + efi_guid_t tcg2_guid = EFI_TCG2_PROTOCOL_GUID; + efi_guid_t linux_eventlog_guid = LINUX_EFI_TPM_EVENT_LOG_GUID; + efi_status_t status; + efi_physical_addr_t log_location, log_last_entry; + struct linux_efi_tpm_eventlog *log_tbl; + size_t log_size, last_entry_size; + efi_bool_t truncated; + void *tcg2_protocol; + + status = efi_call_early(locate_protocol, &tcg2_guid, NULL, + &tcg2_protocol); + if (status != EFI_SUCCESS) + return; + + status = efi_call_proto(efi_tcg2_protocol, get_event_log, tcg2_protocol, + EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2, + &log_location, &log_last_entry, &truncated); + if (status != EFI_SUCCESS) + return; + + if (!log_location) + return; + + /* + * If the logs are empty, we still populate the EFI table to surface + * this information to userland. + */ + if (!log_last_entry) { + log_size = 0; + } else { + /* + * get_event_log only returns the address of the last entry. + * We need to calculate its size to deduce the full size of + * the logs. + */ + last_entry_size = sizeof(struct tcpa_event) + + ((struct tcpa_event *)log_last_entry)->event_size; + log_size = log_last_entry - log_location + last_entry_size; + } + + /* Allocate space for the logs and copy them. */ + status = efi_call_early(allocate_pool, EFI_RUNTIME_SERVICES_DATA, + sizeof(*log_tbl) + log_size, &log_tbl); + + if (status != EFI_SUCCESS) { + efi_printk(sys_table_arg, + "Unable to allocate memory for event log\n"); + return; + } + + memset(log_tbl, 0, sizeof(*log_tbl) + log_size); + log_tbl->size = log_size; + log_tbl->version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2; + memcpy(log_tbl->log, (void *)log_location, log_size); + + status = efi_call_early(install_configuration_table, + &linux_eventlog_guid, log_tbl); + if (status != EFI_SUCCESS) + goto err_free; + return; + +err_free: + efi_call_early(free_pool, log_tbl); +} + +void efi_retrieve_tpm2_eventlog(struct boot_params *boot_params, + efi_system_table_t *sys_table_arg) +{ + /* Only try to retrieve the logs in 1.2 format. */ + efi_retrieve_tpm2_eventlog_1_2(boot_params, sys_table_arg); +} diff --git a/include/linux/efi.h b/include/linux/efi.h index 8dc3d94a3e3c..5eaaa68ac58a 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -472,6 +472,26 @@ typedef struct { u64 get_all; } apple_properties_protocol_64_t; +typedef struct { + u32 get_capability; + u32 get_event_log; + u32 hash_log_extend_event; + u32 submit_command; + u32 get_active_pcr_banks; + u32 set_active_pcr_banks; + u32 get_result_of_set_active_pcr_banks; +} efi_tcg2_protocol_32_t; + +typedef struct { + u64 get_capability; + u64 get_event_log; + u64 hash_log_extend_event; + u64 submit_command; + u64 get_active_pcr_banks; + u64 set_active_pcr_banks; + u64 get_result_of_set_active_pcr_banks; +} efi_tcg2_protocol_64_t; + /* * Types and defines for EFI ResetSystem */ @@ -622,6 +642,7 @@ void efi_native_runtime_setup(void); #define EFI_MEMORY_ATTRIBUTES_TABLE_GUID EFI_GUID(0xdcfa911d, 0x26eb, 0x469f, 0xa2, 0x20, 0x38, 0xb7, 0xdc, 0x46, 0x12, 0x20) #define EFI_CONSOLE_OUT_DEVICE_GUID EFI_GUID(0xd3b36f2c, 0xd551, 0x11d4, 0x9a, 0x46, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d) #define APPLE_PROPERTIES_PROTOCOL_GUID EFI_GUID(0x91bd12fe, 0xf6c3, 0x44fb, 0xa5, 0xb7, 0x51, 0x22, 0xab, 0x30, 0x3a, 0xe0) +#define EFI_TCG2_PROTOCOL_GUID EFI_GUID(0x607f766c, 0x7455, 0x42be, 0x93, 0x0b, 0xe4, 0xd7, 0x6d, 0xb2, 0x72, 0x0f) #define EFI_IMAGE_SECURITY_DATABASE_GUID EFI_GUID(0xd719b2cb, 0x3d3a, 0x4596, 0xa3, 0xbc, 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f) #define EFI_SHIM_LOCK_GUID EFI_GUID(0x605dab50, 0xe046, 0x4300, 0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23) @@ -634,6 +655,7 @@ void efi_native_runtime_setup(void); #define LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID EFI_GUID(0xe03fc20a, 0x85dc, 0x406e, 0xb9, 0x0e, 0x4a, 0xb5, 0x02, 0x37, 0x1d, 0x95) #define LINUX_EFI_LOADER_ENTRY_GUID EFI_GUID(0x4a67b082, 0x0a4c, 0x41cf, 0xb6, 0xc7, 0x44, 0x0b, 0x29, 0xbb, 0x8c, 0x4f) #define LINUX_EFI_RANDOM_SEED_TABLE_GUID EFI_GUID(0x1ce1e5bc, 0x7ceb, 0x42f2, 0x81, 0xe5, 0x8a, 0xad, 0xf1, 0x80, 0xf5, 0x7b) +#define LINUX_EFI_TPM_EVENT_LOG_GUID EFI_GUID(0xb7799cb0, 0xeca2, 0x4943, 0x96, 0x67, 0x1f, 0xae, 0x07, 0xb7, 0x47, 0xfa) typedef struct { efi_guid_t guid; @@ -1504,6 +1526,9 @@ static inline void efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg) { } #endif +void efi_retrieve_tpm2_eventlog(struct boot_params *boot_params, + efi_system_table_t *sys_table); + /* * Arch code can implement the following three template macros, avoiding * reptition for the void/non-void return cases of {__,}efi_call_virt(): @@ -1571,4 +1596,14 @@ struct linux_efi_random_seed { u8 bits[]; }; + +#define EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2 0x1 +#define EFI_TCG2_EVENT_LOG_FORMAT_TCG_2 0x2 + +struct linux_efi_tpm_eventlog { + u32 size; + u8 version; + u8 log[]; +}; + #endif /* _LINUX_EFI_H */ -- 2.14.1.581.gf28d330327-goog